One of these renders was made using 5 infinite lights.

The other was made using everything what PoserPro 2010 could throw at it. (IDL, tone mapping, etc)

I guess my "Standard Poser lighting skills" must be exceptional then, because, even though I really tried, I can't really see any advantage in those new "features".

The real problem is that GC and multi shader skin nodes would only work properly if we all use standardised textures for everything as well as identical monitors.
(And have all the same color perception)

The caucasian skin textures I use look perfect if viewed outside of Poser on my CRT monitor.
(Which displays 99% of all the photographs I find on the web correctly. Unlike my overly bright LCD)

If I crank up gamma, they look bleached out.

Now the lights I use in Poser neither add nor substract from the skins' original "lightness".

So why  would I want Poser to artificially "correct" a texture that already looks perfect ?
Either by shaders or global GC ?

Yes, of course, if you just use those default deep orange caucasian skin textures most people sell (Including DAZ), they will look like cr*p unless you seriously crank up Poser lights or add a gazillion of shader nodes to "compensate".
(Or use an LCD monitor with too much gamma)

Same for any other textured item you use in your scene.

So the first step is to look at all those textures OUTSIDE of Poser and, if necessary, correct them until they look right on your monitor.

Once you've done that,  working "inside" Poser will be a lot easier.